---
title: "Self Assessment"
url: https://www.boruconsulting.com/glossary/self-assessment
type: DefinedTerm
role: obligation
jurisdiction: [UK]
reviewed: 2026-11-10
modified: 2026-11-10
---

# Self Assessment

Role: Obligation | Jurisdiction: UK

The UK system under which an individual with income or gains not fully taxed at source files an annual tax return and pays the tax it calculates. Leaving the UK does not end it: a person with UK income, or who needs to claim non-residence or split-year treatment, usually still files.

A non-resident reports their residence position on the SA109 residence pages, which HMRC’s own free online service does not accept, so the return has to go through commercial software or an agent.

## Legal basis
- Taxes Management Act 1970, s.8

## Related concepts
- Distinct from: [Company Tax Return (CT600)](https://www.boruconsulting.com/glossary/company-tax-return) (the individual’s return, not the company’s)
- Related: [Split Year Treatment](https://www.boruconsulting.com/glossary/split-year-treatment)
- Related: [Statutory Residence Test (SRT)](https://www.boruconsulting.com/glossary/statutory-residence-test)

## Analysis that discusses it
- [The UK Self Assessment deadline when you live abroad](https://www.boruconsulting.com/blog/uk-self-assessment-deadline-non-resident) (Regulatory Intelligence, 2026-10-31)
- [The Non-Resident Landlord Scheme is not a Making Tax Digital exemption](https://www.boruconsulting.com/blog/non-resident-landlord-scheme-mtd-quarterly-updates) (Taxation Strategy, 2026-08-07)
- [UK Pillar Two. The 2025 Amendments and the First MTT and DTT Filing](https://www.boruconsulting.com/blog/uk-pillar-two-2025-amendments-first-filing) (Corporate Structuring, 2026-06-02)
- [A UK-to-UAE pre-exit year is an architecture, not a checklist](https://www.boruconsulting.com/blog/pre-exit-year-checklist-uk-to-uae-hnwi) (Private Wealth, 2026-05-29)
- [Capital gains tax on Dubai property for a UK resident](https://www.boruconsulting.com/blog/cgt-dubai-property-uk-resident) (Taxation Strategy, 2026-08-31)
- [Foreign income and the £50,000 Making Tax Digital threshold](https://www.boruconsulting.com/blog/foreign-income-mtd-threshold-uk-expats) (Taxation Strategy, 2026-08-08)
- [Making Tax Digital and the non-resident landlord in 2026](https://www.boruconsulting.com/blog/mtd-itsa-non-resident-landlord-2026) (Regulatory Intelligence, 2026-08-07)
- [Your UK Home after moving to Dubai. Capital gains, Inheritance Tax and the Tie](https://www.boruconsulting.com/blog/selling-uk-property-after-moving-to-dubai) (Taxation Strategy, 2026-06-15)

Canonical: https://www.boruconsulting.com/glossary/self-assessment

---
Source: https://www.boruconsulting.com/glossary/self-assessment